Equivalent blackbody temperature
From AMS Glossary
equivalent blackbody temperature
So defined, the equivalent blackbody temperature TE is given bywhere E is the radiant flux density emitted by the body, with SI units of watts per square meter, and σ (5.670 × 10-8 W m-2K-4) is the Stefan–Boltzmann constant. This definition is not restricted to solid bodies but applies also to gases and liquids.